docs: document limitation of action

close #1994

doc/telescope.txt

@@ -2380,6 +2380,8 @@ actions.edit_register({prompt_bufnr})      *telescope.actions.edit_register()*
 actions.paste_register({prompt_bufnr})    *telescope.actions.paste_register()*
     Paste the selected register into the buffer
 
+    Note: only meant to be used inside builtin.registers
+
 
     Parameters: ~
         {prompt_bufnr} (number)  The prompt bufnr

lua/telescope/actions/init.lua

@@ -431,6 +431,8 @@ actions.edit_register = function(prompt_bufnr)
 end
 
 --- Paste the selected register into the buffer
+---
+--- Note: only meant to be used inside builtin.registers
 ---@param prompt_bufnr number: The prompt bufnr
 actions.paste_register = function(prompt_bufnr)
   local selection = action_state.get_selected_entry()